Our custom 30ml bottle boxes are built around the bottle, not around a stock size. They suit serums, tinctures, facial oils, essential oils and liquid supplements, and they are cut to fit standard 30ml (1 fl oz) dropper bottles so the bottle sits snug rather than sliding. A typical 30ml Boston round measures around 1.5 inches across and 3.5 to 3.9 inches tall with the dropper cap fitted, which usually calls for an interior around 1.75″ x 1.75″ x 3.9″. Dropper bulb height varies between suppliers, so send your bottle specs or a sample and we size the dieline to it.